I have never understood quite why the Modern Antiquarian is so keen to keep to the prehistoric straight and narrow. The old time antiquarians didn't restrict themselves in that way - they were interested in anything and everything of a venerable age.
Whereas you can never be certain about just how long wells and springs have been sacred or holy, you can be certain that they are as old as the local geology. Its much more difficult to defend the inclusion of hill figures apart from Uffington, but then losing Cerne Abbas would leave your HH man in a strange position. Turf mazes are medieval without doubt. The really dodgy sites are the spurious cup marks and natural rocks that are declared to be "standing stones"
If you want to be purely prehistoric then clearly you have a great deal of purging to do, but why remove features that members find interesting?
Why restrict yourself so narrowly? Your decision of course, but at least ask yourself why. Doesn't affect me as my main interest lies in Holy Wells and the early medieval and so I post my photos elsewhere.